Hands-on Activity Acid Rain Effects

Learning Objectives

After this activity, students should be able to:

• Discuss how engineers are working to prevent pollution and acid rain.
• Use an indicator to differentiate between acidic, basic and neutral solutions.
• Use their observations to describe the cause-effect relationship of acid rain.
• Observe and describe some of the harmful effects of acid rain on living and non-living items.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS: Next Generation Science Standards - Science

Common Core State Standards - Math

International Technology and Engineering Educators Association - Technology

State Standards

Materials List

Each group needs:

• 1 cup vinegar
• 1 cup distilled water
• 2 medium-sized eggshell pieces
• 2 small green leaves
• 2 paperclips
• 2 small- or medium-sized glass jars
• masking tape and pen (for labeling containers)
• two 1.5-inch strips of wide-range (0-14 pH) litmus paper; since groups need to use the comparison chart included with the litmus container, obtain enough dispensers for each group to have one; litmus paper is available from chemistry supply companies (such as Fisher) and well-equipped hardware stores.
• Acid Rain Effects Worksheet, 1 per student (for recording data and answering questions)

Worksheets and Attachments

Introduction/Motivation

Acid rain is an environmental problem that concerns many environmental and chemical engineers. Engineers are always considering the possible effects of acid rain on the health of humans and the environment when they investigate damage to bodies of water, wildlife, forests and crops, and contamination of the drinking water supply.

Acid rain is defined as any form of wet precipitation (rain, snow, fog, dew or sleet) that has a pH less than 5.6 (on a scale of 0 to 14, with 7 being neutral). Large quantities can also be deposited in a dry form through dust. Acid rain is more acidic than normal rain and forms through a complex process of chemical reactions involving air pollution and water molecules in the air. The two most important pollutants that contribute to the formation of acid rain are nitrogen and sulfur compounds, which react with moisture in the atmosphere to form nitric and sulfuric acid.

The sulfur and nitrogen compounds that contribute to acid rain primarily come from combustion products (burning coal and oil) from large industrial and utility sites. Emissions also come from automobiles and other forms of transportation, and other industrial processes.

The effects of acid rain may not be immediately apparent. For example, at a glance, a lake might look clear and beautiful, but a closer look may reveal few living organisms. Some species of fish cannot survive in water with a pH of less than 5. Clams, snails, crayfish and other crustaceans, brook trout, walleyed pike and bullfrogs are especially sensitive to acid in their water supply. Thus, the pH does not have to decrease very much before fish cannot survive. Insects, birds and mammals are also highly affected by acid rain. Acid rain can alter soil chemistry, nutrient availability and plant growth. In their weakened condition, trees and shrubs become vulnerable to insects, diseases and fungus infestations. For more information, see the Acid Deposition Reading and Approximate pH of Common Substances References Sheet.

One way that we can help prevent acid rain is by burning less fossil fuel. Some types of industries that burn a lot of coal and oil include large power plants, and paper and wood processing plants. Engineers have helped to develop laws that prevent or limit large factories and industries from burning fossil fuels or that require them to minimize their pollutant output. Engineers have also developed many useful technologies to help industry reduce the harmful pollutants in the air, but the companies must adhere to the laws and use these technologies.

Procedure

Before the Activity

• Practice this activity at home prior to using it in your classroom.
• Gather materials and make copies of the Acid Rain Effects Worksheet.

With the Students

1. Divide the class into groups of four students each.
2. Distribute supplies to each group.
3. Ask students to use the pH paper to measure the pH of the vinegar and the distilled water, and record it on their worksheets.
4. Ask the students to make some predictions. If vinegar contains acid (acetic acid), then how will the items placed in vinegar change? If these items are placed in water, will they change in the same ways as in the vinegar?
5. Have students use masking tape and pens to label one jar "vinegar" and the other one "water."
6. Pour 1 cup of vinegar into the vinegar jar. Place a paperclip, piece of eggshell and a green leaf in the vinegar. Put the lid on the container.
7. Pour 1 cup of distilled water into the water jar. Place a paperclip, piece of eggshell and a green leaf in the distilled water. Put the lid on the container.
8. Let the jars sit overnight on a windowsill or protected area.
9. The next day, remove the container lids. Observe any changes in the condition of the items in the jars. Ask students to write their observations on their worksheets. (Expected results: In the water containers, the items show no noticeable changes. In the vinegar jars, the eggshells are soft, the leaf may have brown spots [this may take a few days], and the paperclip shows no noticeable changes.)
10. After one week, look for more changes. Make observations again, as often as you wish.
11. Direct students to complete the questions on their worksheets and/or discuss as a class.

Assessment

Pre-Activity Assessment

Prediction: Using the Acid Rain Effects Worksheet, ask students to record some predictions. If vinegar contains acid (acetic acid), how will the items placed in vinegar change? If these items are placed in water, will they change in the same ways as in vinegar?

Activity Embedded Assessment

Observations: Using the Acid Rain Effects Worksheet, ask students to record their observations of what happens to the items after one day and one week.

Worksheet: Ask students to complete the questions on their Acid Rain Effects Worksheets. You may wish to discuss some of these as a class.

Post-Activity Assessment

It's a Community Issue!: Ask students to write a detailed description of how acid rain would affect their world. For example, the tree on the playground, the pencil they use, a local crop or a local park, etc.

Safety Issues

Remind students not to taste the "acid rain" even though it is made of vinegar.

Troubleshooting Tips

Allow at least 24- 48 hours for the effects of the vinegar to appear in the leaf and eggshell.

Activity Extensions

Look at photographs on the Internet or in books/magazines that show evidence of damage due to acid rain. Discuss the general and specific types of damage to living and non-living things.

If you know of physical evidence of acid rain in your community, arrange a field trip to see and examine it.

Observe the effects of acid rain on living plants. Water a control plant with distilled water and the other with vinegar water (1 tablespoon vinegar per 1 cup distilled water). You can also water them both with distilled water and spritz them with distilled water or vinegar water to more accurately simulate rain. Discuss/explore materials that could be added to the soil to counteract the effects of the acid rain.

Try the vinegar experiment with a whole, raw egg, or a piece of chalk.

Make a third solution (perhaps of lemon juice or a vinegar/water mix) and compare/rank the results or make a bar graph.

Have students read and discuss the Acid Deposition Reading.

Activity Scaling

• While this activity is appropriate for all grade levels, for lower grades, consider observing and discussing the effects as a class. Encourage students to draw pictures of the results (and for assessment).
• For upper grades, have students measure a precise volume of vinegar and water.
• For upper grades, ask students to use graph paper (this may be easier with irregular shapes), or measure length and width to determine the area of the eggshell and leaf.
• For upper grades, have students measure the mass of the eggshell, leaf and paperclip before and after the experiment.

References

Copyright

Contributors

Supporting Program

Acknowledgements

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education and National Science Foundation (GK-12 grant no. 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.